Means for muffling exhaust of pressure cooking apparatus

ABSTRACT

A readily cleanable muffler is provided for receiving the greasy steam exhaust of a pressure cooking apparatus and for venting the exhaust in a quiet manner. The muffler is detachable for cleaning and for removal of collected condensate.

United States Patent Pottinger et al.

MEANS FOR MUFFLING EXHAUST OF PRESSURE COOKING APPARATUS Inventors: Eugene A. Pottinger, Louisville;

Winston lL. Shelton, Jeffersontown, both of Ky.

Commercial Appliances, Inc., Jeffersontown, Ky.

Filed: June 8, 1973 Appl. No.: 368,246

Assignee:

U.S. C] 1126/299 A Int. Cl A47j 36/38, F24c 15/20 Field of Search 126/299; 98/115 K; 99/337 References Cited UNITED STATES PATENTS Miller 126/299 A Keogh l26/299 A Kauffman 126/299 A Primary ExaminerEdward G. Favors Attorney, Agent, or Firm-William E. Sherwood 57] ABSTRACT A readily cleanable muffler is provided for receiving the greasy steam exhaust of a pressure cooking apparatus and for venting the exhaust. in a quiet manner. The mufiler is detachable for cleaning and for removal of collected condensate. 1

6 (Ilaims, 5 Drawing Figures MEANS FOR MUFFLING EXHAUST or PRESSURE CQOKING APPARATUS BACKGROUND OF THE INVENTION In the cooking of various foodstuffs by immersion in hot liquid fats, as illustrated for example by U. S. Pat. No. 3,677,170, it is necessary to provide for the venting of hot vapors at certain times. Various forms of condensers and mufflers have been suggested for confining such vapors, but to the best of our knowledge they are incapable of providing the advantages inherent in the present invention.

As will be appreciated, the sudden expulsion of a blast of hot vapor from a relief valve may startle the op erator of the cooking apparatus and result in interruption of his work. Also the vented hot vapor upon condensing may leave a greasy film which will later have to be cleaned from surrounding surfaces. Moreover, any muffling or condensing apparatus attached to the cooking apparatus will occupy space which must be provided for in the installation of the cooking apparatus, thus placing a premium upon use ofa compact and effective muffling means. i

It is these and similar disadvantages of conventional muffling means which it is a purpose of the present invention to overcome.

SUMMARY The muffler comprises a large lower space communieating with a smaller chimney-like space which has a small vent opening at its top. The configuration of the smaller space is such as to enclose a vertically arranged open-ended vent assembly at the rear of the cabinet of the cooking apparatus. The muffler unit is detachable from theventassembly and hangs fromthe top of the assembly in contact with the rear wall of the cabinet.

Among the objects of the invention are the provision of an improved muffler which is detachably positioned at the rear of a pressure cooking apparatus in a compact space-saving arrangement; the provision of an improved muffler which serves jointly to silence the escape of gas from a pressure cooking apparatus and to collect condensate; the provision of an improved muffler which is sanitary and which can be easily cleaned after use; and the provision of an improved muffler which can be attached or detached with a minimum of manual effort.

These and other objects and advantages of the invention will become more apparent as the description proceeds and when considered in conjunction with the accompanying drawings in which:

FIG. is a perspective view showing the muffler in operative position on the vent assembly of a pressure cooking apparatus.

FIG. 2 is a perspective view of the vent assembly with the muffler removed.

FIG. 3 is a diagrammatic view indicating the flow of gas during the muffling action.

FIG. 4 is an elevation view of the side of the muffler facing the cabinet, and

FIG. 5 is a perspective view ofa second form'of muffler.

Referring first to FIG. 1 a pressure cooking apparatus having a cabinet with a vertical back wall 11 encloses the cooking vessel. The top 12 of the cabinet includes an elevated enclosure 13 housing various control means and provided with a pair of removable service panels ]l4, 15 at its rear. As seen in FIG. 2, when these panels are raised, access is provided to the controls including the vent solenoid 116 which in conjunction with a dead weight member 17 associated with a ball valve 18 effects venting from the cooking vessel as described more fully in the afore-mentioned US. Pat. No. 3,677,170. To direct such vented gases, a generally vertical vent assemblyopen at its upper and lower ends 19, 20 respectively and closed by a removable panel 21 is provided. This open-ended assembly with its back wall 22 fastened to the cabinet enclosure 13 and with its side walls 23, 24, serves as a rigid structure over which the chimney portion of the muffler, later to be described, is adapted to be mounted, and as will be noted, the upper end of the vent assembly extends above the top most portion of the elevated housing 13.

As shown in FIG. 3, a sealing means comprising a rectangular flap of flexible material 30, such as synthetic rubber, is attached at its upper edge to the rear of the enclosure 13 and hangs downwardly against the rear wall 11 of the cabinet below the lower end 20 of the vent assembly. Conveniently, this flap may be attached by screws which also mount a shallow baffle 31 within the confines of the vent assembly.

For use with the described structure, a one piece muffler is provided for mounting in the manner best shown in FIG. I. Preferably the muffler is made of a material, such as stainless steel, which can be readily cleaned with a steam jet, and comprises essentially an upper chimney portion 35 of relatively small volume sufficient to enclose the vent assembly and a lower muffling portion 36 of relatively large volume. As indicated in FIG. 4, the lower portion comprises a flat wall 40 having an aperture 41 cut therein and of a size less than the size of the flap 30. The hollow chimney portion includes a front wall 42 and side walls 43, 44 whose edges lie in the same plane as that of wall 40. To enhance the efficiency of muffling, the lower portion includes a bottom 45 and a front wall 46 offset outwardly from the wall 42 of the chimney portion, and the lower portion in addition extends laterally a substantial distance in both directions from its junction with the chimney portion. This lateral extension provides for a large muffling space without adding appreciably to the floor space required for installation of the cooking apparatus.

At its upper end the chimney portion includes a top plate 50 having a downwardly directed flange 51 spaced from the wall 42 thus to leave a space 52 through which gas is vented. Conveniently, an L shaped member having a back wall 53 projecting below plate 50 and a top portion 54 serving as a handle, is at tached to the top plate 50. As seen in FIG. 3, the muffler may easily be installed by hooking the back wall 53 over the top of wall 22 of the vent assembly and allowing the muffler to swing into vertical position at which time the opening 41 is closed by the flap 30 and the edges of the walls 43, 44 contact the service panels 14, 15 of the cabinet. The dimensions of the chimney portion moreover, are chosen so that in its operative position the walls 43, 44 of the chimney portion preferably are in contact with the respective walls 24, 23 of the vent assembly.

With the muffler thus installed, greasy vapor expanding through valve 18 rises through the vent assembly,

strikes the top 50 of the muffler, and seeks a larger space into which it may expand. It then flows downwardly into the larger space of the muffler, moves about in that larger lower space, and then passes upwardly to bleed outwardly into the ambient atmosphere through the small vent 52. The baffle 31 serves to assist in causing turbulent flow. During this travel the sound of the surge of gas is substantially silenced and in addition its temperature is lowered by contact with the surfaces of the muffler. Since the lower portion of the muffler is closed below the opening 41, condensate may collect within the muffler. Periodically, as at the end of a day's operation of the cooking apparatus the muffler is lifted from its hanging position on the vent assembly, collected condensate is drained therefrom, and by means of a steam jet blown through the opening 41 the interior of the muffler unit is cleaned. At this same time the vent assembly panel 21 may be removed and cleaning of the weight 17 and interior of the vent assembly may be effected.

Other shapes of the muffler may, of course, be employed without departing from the invention. As indicated in FIG. 5, a muffler having a chimney portion 60 attached to a larger lower portion 61 of disc-like form may be employed.

Obviously many modifications and variations of the present invention are possible in the light of the above disclosure. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. Means for muffling the exhaust of a pressure cooking apparatus having a cabinet and comprising in combination, a generally vertical vent assembly open at each end and directing gas vented from a cooking chamber within said cabinet, a removable muffler having a relatively small upper chimney portion surrounding and supported upon the upper portion of said vent assembly and communicating with a relatively large lower muffling portion extending below and in communication with the lower end of said vent assembly, said chimney portion having an opening at its upper end communicating with the lower larger portion of said muffler and through which gas is vented.

2. Apparatus as defined in claim 1 wherein said vent assembly and muffler are disposed at the rear wall of the cabinet enclosing the cooking chamber, said lower portion of said muffler having an aperture facing said rear wall, and a sealing means interposed between said rear wall and said muffler and covering said aperture.

3. Apparatus as defined in claim 1 wherein said lower portion of said muffler extends transversely from the lower end of said vent assembly.

4. Apparatus as defined in claim 1 wherein said lower portion of said muffler projects farther from said cabinet than said vent assembly projects therefrom.

5. Apparatus as defined in claim 1 wherein said lower portion of said muffler comprises a receptacle in which condensate of the vented gas is collected.

6. Apparatus as defined in claim 1 wherein said muffler is constructed of a metal adapted to cool the vented gas and to aid in condensing of hot vapor. 

1. Means for muffling the exhaust of a pressure cooking apparatus having a cabinet and comprising in combination, a generally vertical vent assembly open at each end and directing gas vented from a cooking chamber within said cabinet, a removable muffler having a relatively small upper chimney portion surrounding and supported upon the upper portion of said vent assembly and communicating with a relatively large lower muffling portion extending below and in communication with the lower end of said vent assembly, said chimney portion having an opening at its upper end communicating with the lower larger portion of said muffler and through which gas is vented.
 2. Apparatus as defined in claim 1 wherein said vent assembly and muffler are disposed at the rear wall of the cabinet enclosing the cooking chamber, said lower portion of said muffler having an aperture facing said rear wall, and a sealing means interposed between said rear wall and said muffler and covering said aperture.
 3. Apparatus as defined in claim 1 wherein said lower portion of said muffler extends transversely from the lower end of said vent assembly.
 4. Apparatus as defined in claim 1 wherein said lower portion of said muffler projects farther from said cabinet than said vent assembly projects therefrom.
 5. Apparatus as defined in claim 1 wherein said lower portion of said muffler comprises a receptacle in which condensate of the vented gas is collected.
 6. Apparatus as defined in claim 1 wherein said muffler is constructed of a metal adapted to cool the vented gas and to aid in condensing of hot vapor. 